Motion video signal processing for recording or reproducing – Local trick play processing – With randomly accessible medium
Reexamination Certificate
1998-01-27
2001-09-04
Tran, Thai (Department: 2615)
Motion video signal processing for recording or reproducing
Local trick play processing
With randomly accessible medium
C348S901000, C358S908000
Reexamination Certificate
active
06285818
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a commercial detection apparatus and commercial detection method which can effectively applied to an video recording/reproduction apparatus such as a home video tape recorder.
2. Description of the Prior Art
When reproducing a television broadcast program recorded on a video recording apparatus such as a video tape recorder, a user desires to see the television broadcast program alone, deleting commercials. Thus, it has become possible to record or reproduce a television program deleting commercials.
However, the conventional commercial detection method applied to a home video tape recorder is a simple method which cannot automatically distinguish a television main program from commercials, and the user should manually operate the video tape recorder so as to accurately delete commercials.
The conventional simple commercial detection method will be explained below with reference to an attached drawing.
FIG. 1
is a block diagram showing an example of a commercial detecting circuit
20
according to the conventional commercial detecting method mounted on a video tap recorder or the like.
In
FIG. 1
, an RF signal inputted from an antenna
21
which is an RF input terminal is demodulated by a tuner
22
, and a sound broadcasting signal is isolated from the demodulated television broadcasting signal. This sound broadcasting signal is supplied to a soundless section check circuit
23
and a sound multiplexing mode signal detecting circuit
24
.
The soundless section check circuit
23
demodulates the sound broadcasting signal into a sound base band signal, whose amplitude level is used to detect soundless sections, and it is determined whether its detection time interval agrees with a predetermined rule.
Generally, a commercial interval is about 15 seconds multiplied by an integer. If the temporal interval of appearance of the soundless sections is 15 seconds multiplied by an integer, it can be determined that a reception signal is a commercial. As a soundless section may occur at other than a start and an end of a commercial, in order to prevent to erroneously identify it as a commercial when it is 15 seconds multiplied by an integer, the aforementioned interval check is carried out on the condition that soundless section of 15 seconds multiplied by an integer is repeated, for example, twice, before identifying it as a commercial and outputting a soundless section check output, i.e., a commercial detection output.
On the other hand, the sound multiplexing mode signal detection circuit
24
detects a current mode of the inputted sound broadcasting signal, i.e., monophonic, stereo, or two-language mode and encodes the current mode, for example, into a 2-bit digital data for output such as ‘00’ for monophonic, ‘01’ for stereo, and ‘10’ for the two-language mode.
Moreover, a main program detecting circuit
25
includes a delay circuit
26
, D flip-flop
27
, and a pulse generating circuit
28
. An output from the sound multiplexing signal detecting circuit
24
is supplied to the delay circuit
26
and delayed by several seconds before introduced to the input terminal of the D flip-flop.
On the other hand, this main program detecting circuit
25
supplies the pulse generating circuit
28
with the interval check output from the soundless section check circuit
23
for observing this check output for about two minutes. If no soundless section check output, i.e., if no commercial detection output is present, it is determined that the current reception signal is not a commercial but a main program and a corresponding pulse is generated. This pulse is introduced to a clock terminal of the aforementioned D flip-flop. Thus, the output of the D flip-flop always maintain an encoding value of the sound multiplexing mode of the main program.
It should be noted that the reason why the detection output of the sound multiplexing mode is delayed by the delay circuit
26
is that it is predicted that a change will occur in the sound multiplexing mode when a commercial detection which is a soundless detection is outputted, and it is necessary to prevent that the sound multiplexing mode detection output becomes unstable when the commercial detection output is supplied to the clock terminal of the D flip-flop.
Moreover, the reason why about two minutes are set for observing the commercial detection output in the soundless section check circuit
23
is that generally a commercial is completed within one minute and it is preferable to reduce the response time. An output of the aforementioned D flip-flop
27
is the output of the main program mode output circuit
25
.
A mode comparator circuit
29
compares the output of the main program mode detecting circuit
25
to the output of the sound multiplexing mode signal detecting circuit
24
. If they coincide, it is determined that a current reception signal is a main program; and if not, it is determined that the current reception signal is a commercial. The result of the comparison is outputted.
In general, when the sound multiplexing mode is changed from the main program mode to another mode and after the mode is not returned to the main program mode but to a third mode, it is predicted that it is a switching point of the programs. In this case, the mode comparator circuit
29
outputs a decision result that main program/commercial indefinite.
The aforementioned commercial detecting circuit
20
carries out commercial detection only according to sound information i.e., sound multiplexing mode and soundless section interval. This often causes an erroneous detection.
Especially when the main program is a stereo broadcasting or two-language broadcasting, there is no method to prevent an erroneous detection. As has been described above, it is known to detect a commercial according to sound information but it is only simplified method and there has been no definite means to enhance the detection accuracy.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a commercial detection apparatus and detection method capable of accurately determine whether a current reception television broadcasting signal is a commercial or a main program.
The commercial detection apparatus according to the present invention detects with soundless section detecting means a soundless section in a received audio signal, detects with scene change detecting means a scene change point of an image from a video signal during said soundless section, detects with scene change interval detecting means whether a time interval of the scene change points agrees with a predetermined rule, and detects with sound multiplexing mode detecting means a sound multiplexing mode of the received audio signal.
Moreover, the commercial detection method according to the present invention, in order to achieve the aforementioned object, detects a soundless section in a received audio signal, detects a scene change point of an image from a received video signal during the soundless section; and detects that a time interval of the scene change points agrees with a predetermined rule and a sound multiplexing mode of said received audio signal is stereo.
More specifically, the present invention is based on that a soundless section of 0.1 to 2 seconds is present with a high probability between a main program and a commercial or between commercials; that a scene change point of an image is present during the soundless section; that each commercial lasts for 15 seconds multiplied by an integer; and that during a commercial broadcast section, the sound multiplexing mode is a stereo mode. Consequently, if the scene change point during a soundless section appears for every 15 seconds multiplied by an integer and if the section of 15 seconds multiplied by an integer is on a stereo broadcast mode, then the section is determined to be a commercial section.
REFERENCES:
patent: 4750213 (1988-06-01), Novak
patent: 5696866 (1997-12-01), Iggulden et al.
patent: 5911029 (1999-06-01), Sakaguchi et al.
paten
Akiba Toshiya
Arai Naohisa
Murabayashi Noboru
Ohta Masashi
Suito Taro
Frommer William S.
Frommer Lawrence & Haug LLP.
Sony Corporation
Tran Thai
LandOfFree
Commercial detection which detects a scene change in a video... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Commercial detection which detects a scene change in a video..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Commercial detection which detects a scene change in a video... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2435417